<div class="chat-container">
  <div class="chat mat-elevation-z4">
    <mat-sidenav-container>
      <mat-sidenav class="mat-elevation-z2" mode="side" opened="true" #chatSidenav>
        <app-contacts [chats]="chats" (onActiveChat)="onActiveChat($event)"></app-contacts>
      </mat-sidenav>
      <app-chat [activeChat]="activeChat" [chatSidenav]="chatSidenav" (onSendChat)="sendChat($event)"></app-chat>
    </mat-sidenav-container>
  </div>
</div>